---
title: "CVE-2026-84003: Microsoft Authentication Library (MSAL) for Node.js - Authentication Bypass"
description: "Microsoft Authentication Library (MSAL) for Node.js contains an authentication bypass caused by capture-replay attacks, letting unauthorized attackers perform spoofing over a network, exploit requires network access."
url: https://panop.io/threat-heartbeat/CVE-2026-84003/
---

# CVE-2026-84003 Microsoft Authentication Library (MSAL) for Node.js - Authentication Bypass

Microsoft Authentication Library (MSAL) for Node.js contains an authentication bypass caused by capture-replay attacks, letting unauthorized attackers perform spoofing over a network, exploit requires network access.

CVSS base score 7.4 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.60% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-84003)

## Details

Type

Authentication Bypass

Impact

Broken Authentication

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Published

8 September 2026

Updated

15 October 2026

Weakness

[CWE-294](https://cwe.mitre.org/data/definitions/294.html)

## Vendor fix

Update to the latest version of Microsoft Authentication Library (MSAL) for Node.js.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-84003](https://nvd.nist.gov/vuln/detail/CVE-2026-84003)
- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-84003](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-84003)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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